Press eor plastic materials



June 2, 193i. E. L .MEssLER PRESS FOR PLASTIC MATERIALS Filed May 9. 1929 FIB. 1I

INVENToR Eugene L. Mess ler Patented `lune 2, 1931 EUGENE L. MESSLER, F PITTSBURGH, PENNSYLVANIA PRESS FOR PLASTC MATERIALS Application filed VMay 9, 1929. Serial No. 361,619.

This inventionrelates to a press for plastic materials, and more particularly to a die structure for use in seggar pressers as employed in the manufacture of ingot mold hot tops. Y

Ingot mold hot tops, according to their preferred form, require a seating shoulder, so that the hot top-mayrest on an ingot mold with a small portion thereof projecting -into the bore of the mold, and the major portion thereof projecting upwardly from the mold. This shoulder is formed by removing material from the outer and lower edge of the hot top, so that either a plurality of small ledges arecformed, or a continuous ledge is formed.V

The conformation of a short portion of the hot top to produce these ledges, presents the chief problem in the manufacture of hot tops in a seggar press. As the clay used contains $0 a great-deal of moisture during the period of pressing, the use. of a continuous ring of appreciable vertical extent result-s in pulling away the wall lying between such ring and the main body of the plunger, that is of the 15 male forming die, as such die is removed.

A structure obviating such ldifficulty is illustrated and described in patent to Austin L. Moore No. 1,698,603.

The object of the present invention is to provide a simplifiedV structure, which may be used in producing hot topsV having seating ledges of suitable contour, and in forming the seating ledges of hot tops of certain contour and size. A In the accompanying drawings Figure l is a vertical sectional view of the female forming die and an elevation of the male forming die, illustrating one modification 'inl the strucn ture of the male die; Figure Il is a view part- 40 ly in vertical section, and partly in elevation, showing the same die structure in seated or completed pressing position; Figure III is a view taken on the line IIIe-III of Fig. I, showing the male die structure in bottom plan; Figure IV is a view partly in elevation and partly in vertical section, showing the form of hottop pressed by the die structure ofFigures I and Il; Figure V is a View partly in vertical section and partly in elevation, showing the die members in pressing position, and illustratingthe use of a continuous ring on the male die or plunger- Figure VI is a bottom plan view on a reduce scale showing amodified form of hot top made by a slightly modilied die structure; and Figure VII is an elevation of the hot top shown in Fig. Vl.

With reference to Figs. I and II numeral 1 designates the female `die of the press, which may be of any usual form, and reference numeral 2 the clay or other suitable plastic composition therein. Reference numeral 3 designates the plunger or male die proper, and reference numeral l the head carrying the same.

Carried by head 4 are ledge forming die blocks 5. These ledge forming dies, as shown par ticularly in Fig. III, are of a form to produce relatively short corner ledges of moderate depth, or vertical extent.

shown, these die blocks 5 are spaced from the base portion of the male die, or plunger,

a sufficient distance to leave a material space 6 between the die block and body of the plunger.l The die thus cuts out the corners Gai n forming the hot top leaving a relatively thick wallof material in the space 6 adjacent such cut away portion.

By utilizing these dies to produce corner ledges 6b of small peripheral extent, the hot top when pressed is given suficient seating surface, without experiencing the difficulties described above during the withdrawal of the avo

plunger, or male die. The-diii'iculty is idedfor the'reason that the die arrangement is such as to leave a thick wall of material, and because the depth, or vertical extent, of the space, 6 between the body of the plunger and each auxiliary die block is relatively short.

It has also been found that where the male die or plunger is given a relatively great degree of taper, a continuous ring may be utilized, provided that neither the vertical by such die ring horizontal depth of the impression-made e relatively great with ret will be noted by reference to Fig. V

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that the die ring 7 carried by head 4a is soV and narrow, leaving a relatively great body of material between the ring and plunger. It will be noted thatwhile the diering7 is of considerable width in itself, the greater portion of such width seats in an annular recess 8 in the female die la. The effective width of the ring is thus the portion thereof which extends inwardly from the bore lb of the female die. Because of the taper ofthe plunger, clearance is provided immediately upon the beginning of the withdrawing movement thereof. v 4

For the above reason a hot top having an internally tapered bore, and a seating ledge which is relatively narrow and positioned relatively close to the loweredge of the hot top may be made by use of al male die structure with a continuous auxiliary ring. i The draft, or angle of inclination of the male die-is varied in accordance with `the consistency and inherent cohesion of the material used for` the hot tops. Vith the mass commonly used, however, this angle should not be materially less than five degrees, and may be desirably increasedin order to increase the factor of safety in preserving the Vwall portion` or flange 9,.of the ho-t top extending below the seating ledges 14.

After removal of the pressed hot top from the seggar press, and before the same has hardeneila teeming orifice l() is desirably cut in the upper horizontal wall ll of the bot top.

To press the form of hot top shown in Figs. VI and VII'of the drawings, it is not always necessary to employ a continuous ring 7, because additional auxiliary die blocks may be added to the hea-d @between the corner die blocks 5. These blocksare,V

are of relatively great width it may bev seen by the indentations 13 formed thereby that they are of relatively slight effective Width with respect to the wall left by the interval between the die blocks and the surface of the male die proper. y

While the angle of inclination of the male die proper 3, shown in Figures I, II, and III, is shown as equal to that of the male die aro er 3a shown in Figure V such a degree' of taper is not necessary. lith that form of die structure, as with the structure tobe used in forming the hot top of Figs VI and VII, the interruption between the die blocks,

arranged to ,formv a .centrally disposed indentation in plastic lmaterial lying in the female die, and auxiliary male die'means rigidly -mounted on said head and spacedfrom themale die proper; said auxiliary die l means being arranged to cooperate with the female die to form an externalshoulder in the material lying between the male die proper and the interior surface of the female die, and the auxiliaryydie meansbeing so formed thatthe indentation produced thereby isw of slight depth relatively to the depth of the indentation produced by the male die proper, there being an inclination infat least one of the opposed surfaces of the male die proper and the auxiliary male die means of no less than live degrees.

2. In a die structure Yfor use in pressing plastic substances to form ingot mold hot tops the combination of a .female die, a plunger head, a male die proper on said head arranged to form a centrally disposed indentation in plastic material lying in the female die, and auxiliary male die means rigidly mounted on said head and spaced fro-m they male, die proper; said auxiliary die means being arranged to cooperate with the female die to form an extended external shoulder in the material lying between the male die proper and the interior surface of the female die,

and the auxiliary dieV means being so formed that the indentation produced thereby is ofl slight depth relatively to the depth ofthe indentation produced by the'male die proper,

there being an inclination in at least lone of the opposed surfaces of the male die propery and the opposed. auxiliary die means'of no less than five degrees.

3. In a die structure for use kin pressing plastic substances to form ingot mold hot tops the combination of a female die approximately rectangularin horizontal section, a plunger head, a male die proper on said head arranged to form a centrally disposed indentation in plastic material lying in the female die, and auxiliary'male die means comprising corner blocks `rigidly mounted on said head and spaced from themold die proper to cooperate with'the interior of the corners in the female die to formy shoulders at such regions the material between the male vdie proper and the female die; said auxiliary corner blocks being so formed that the indentation produced thereby is of slight depth relatively to the depth of the indentation produced by the male die proper.

In testimony whereof I have hereunto set my hand.

EUGENE L. MESSLER. 

